Educational apparatus



Qct. 6, 1931. P. E. KLoPsTEG EDUCATIONAL APPARATUS Filed May i1, 1929 N W? mlm Patented ct. 6, 1931 UNITED STATES PAUL E. KLOPSTEG, OF CHICAGO, ILLINOIS EDUCATIONAL APPARATUS Application led May 11, 1929. Serial No. 362,345.

The principal object of this invention is to provide simple and sturdy apparatus for use in experiments on the relation of mass ailid velocity in momentum equations, and the li e.

L6 Further objects and advantages of the invention will become apparent as the disclosure proceeds and the description is read in ecnnection with the accompanying drawings, in which Fig. 1 is a plan view of the apparatus set up for demonstrating the relative velocity of different masses acted upon by equal forces;

Fig. 2 is a side elevation of the same at the beginning of the experiment;

' Fig. 3 is a side elevation of the same at an intermediate stage of the experiment;

Fig. 4 is a similar side elevation at the end of the experiment; Fig. 5 is a vertical section taken on the line 5 5 of Fig. 2v, and

Fig. 6 is a fragmentary perspective view illustrating the manner of coupling the cars.

But these specific illustrations and the correspondingly specific description-are used for the purpose of disclosure only, and it is realized that the substance of the invention may be embodied in other forms and put to other uses, all of which are intended to be covered by the appended claims.

Generally speaking, the apparatus comprises two cars, A and B, urged apart by equal forces, and temporarily' coupled by means permitting them to be suddenly released.

Each of the cars includes a channel shaped aluminum casting with the web 10 at the top, and the flanges 11 extending downwardly and mounted on three wheels 12, each on a separate axle 13, journaled on pivot bearings 14, carried by the anges 11.

The car A is equipped with a selected mass 15, and is adjusted to a known standard weight. Car B may, or may not, be accurately.-

adjusted, and is provided with a bar 16 extending along its center and supported byend pieces 17, and is adapted to receive slotted masses 18 to permit its total weight, or mass,

to be varied.

At one end car B has a bar 19 made fast 50 to the flanges 11 by'screws 20, and equipped with tapered prongs 21 about which are coiled helical springs 22.

Car A is equipped with a similar bar 23 secured in a like position and perforated to receive the prongs, but not the springs 22, whereby, when the cars are brought together in the relation shown in Figs. 1 and 2, the springs are compressed between the bars 19 and 23, and are prevented from buckling by the prongs 21.

The bar 23 is also equipped with a pair of hooks 24, located at each side of the center line and projecting towards the car B. These hooks are pinched together at 25 so as to grip a cord 26 stretched between them. 65 The bar 19 on the car B is equipped with a single relatively open hook 27 projecting along the center line of the car, and adapted to engage the cord 26 between the hooks 24.

The track comprises a. beam 28 of channel 70 section having its flanges 29 turned upward and their free edges 30 milled to a suitable curvature.

Two of the wheels 12a-re necessarily located at one side of the car and their peripheries are ground to a curvature slightly greater than the curvature of the edges 30 whereby they will run on a very narrow surface of the track, and will guide the care accurately.

About one-quarter o'f the length from each 8O end the beam 28 is fitted with 'stout base castings 31 having laterally projecting arms 32, equipped with leveling screws 33, whereby the beam is strongly supported, and may be accurately and easily leveled.

Each end of the beam is equipped with a frame, including uprights 34, screwed to the flanges 29, and connected at their upper ends by .the cross arm 35, which projects laterally beyond the flanges 29 and are equipped with 90 buffers comprising` leaf springs 36 of phosphor bronze lying close together, except that at their free ends they are separated, as indicated at 37.

Each of the cars A and B is provided with an angle-shaped cross piece 38, secured to the flanges 11 by screws 39, and having one flange 40 projecting laterally beyond the car, and adapted to be inserted between the 100 springs 36, as the car approaches the end ei" the track.

0 @eration The track is placed on a table, or other suitable support and leveled by means et the -screws 33. A length et cord is stretched across the hooks of car A and forced into the pinched bights 25 thereof, after which the car is placed on the track.

Car I3 is placed on the track and brought somewhat nearer to car A than it appears in Figs. l and 2, during which movement the hook 27 will pass under the cord 2G and upon release of the cars the parts will assume their relations indicated in Figs. l and 2.

It desired, one or more weights 18 are placed on the car B.

`his places the apparatus in condition for a demonstration which may be precipitated by burning or cutting the cord QG which suddenly releases the cars without introducing` any appreciable error due to inadvertent application of force.

rElie springs 22 entend, acting and reacting simultaneously on each ot the cars, and forcing them to travel in opposite directions along the track. Upon approaching` the corresponding end of the track the bar 40 of each car enters between the diverging ends 87 of the springs 36, and the car is brought to rest without either shock or rebound.

One of the flanges 29 may be graduated, or a separate scale may be laid along side it to indicate the position and travel of the cars in suitable units.

IV ith a few repetitions of the operation described, the student can find positions from which the cars will reach the bufers at the same instant. Iii, then, the momentum equation is assumed, and the mass of one car is known, the mass of the second car may be determined. Also, if the mass of the two cars is known the momentum equation may be verilied.

Attention is directed to the fact that features ol novelty in the track and car construction are not separately claimed herein,but are claimed in a copending application tiled February 3, 1930, Serial No. 425,522.

I claim as my invention:

l. In apparatus of the class described, a track, means tor leveling the track, a pair of cars, a friction butiler adjacent to each end of the track adapted to cooperate with the cars to bring them to rest without rebound, means for urging the cars apart with equal iloi-ce applied to each car, and means for coupling the cars against the resistance of the last named means and suddenly uncoupling them.

2. In apparatus of the class described, a car, a prong projecting from the car, a helical spring on the prong, a second car having an opening to receive the prong but not the spring thereon, and means to couple the cars with the spring` compressed and suddenly uncoupling them.

3. In apparatus of the class described, a car, a prong projecting Yfrom the car, a helical spring on the prong, a second. car having an opening to receive the prong but not the spring thereon, and means to couple the cars with the spring compressed and suddenly uncoupling them, including a cord attached to one car and a hook attached to the other car and freely engaged with the cord.

4t. In apparatus or the class described, two cars, resilient means tending to separate them and means for coupling the cars with the resilient means compressed, said coupling means being adapted to be suddenly released.

5. In apparatus of the class described, two cars, means exerting equal force on both cars,

but in opposite directions, and means Afor,

holding the cars against the force, said last named means being adapted to be suddenly released to allow the cars to ily apart.

6. In apparatus of the class described, a

cai', a pinched hook at each side of the center .l

line ot the car adapted to grip a cord extended between tlie two hooks, a second car, an open hook projecting from the center line of the second cai' to receive the cord held by the pinched hook, and means for forcing the cars apart.

7. In apparatus of the class described, a

car, a pinched hook at each side of the center line ot the car adapted to grip a cord extended between the two hooks, a second car, an open hook 1'no]ecting i'om the center line of the second car to receive the cord held by the pinched hook, and a spring at each side of the center line ot the cars urging them apart.

8. In apparatus of the class described.l a

beam, a track on the beam', a scale at one side of the beam, two cars for the track, means ttor urging the cars apart with equal torce on each, and means for temporarily coupling the PAUL E. KLOPSTEG. 

